Chip cards of this type are already in widespread use as telephone cards, health insurance cards, GSM cards, bank cards and credit cards.
The layers of such cards (front and back sides of card) have a costly design. The visible surface of the chip module, with its contact surfaces, constitutes a foreign body in the layout of the front side of the card. This negatively impacts the appearance of the card and detracts from the layout design options. The contact surfaces have a metallization of either gold, silver or palladium; the palladium metallization is silver-colored in appearance. These metals are especially well-suited for forming contact surfaces, because they are inert, and do not oxidize or corrode, and because they permit very low transition resistances to the contacts of the chip card terminal. In addition, gold and palladium, especially with special alloy additives, have high wear resistance. For these reasons, the contact surfaces of chip cards currently use gold and palladium almost exclusively. In layout design, the only choice is thus between chip modules with gold-colored or those with silver-colored surfaces.